After updated to the 1.3 version, which has solved the HiDPI issues, pdf render becomes extremely slow with HiDPI screen (not sure for monitors with normal DPI). It happens quite often that it takes several second to render a PDF page. The whole page is blurring during the render process.
Cannot reproduce this. Does it happen with all documents, or only with particular ones?
(In reply to Oliver Sander from comment #1) > Cannot reproduce this. Does it happen with all documents, or only with > particular ones? Not all documents for sure. It happens to PDF files with lots of plots, which may be the reason why it renders slowly (I should not use the word "ridiculously", it's not that bad). You may try this document https://zenodo.org/record/59178/files/flares_splinter_cs19.tar.gz . The link won't do any harmful things (just a summary of some boring stars).
Marcel: It would be great if you could add the version of Poppler in use. You can check with "rpm -qi libpoppler-qt5-1".
(In reply to Henrik Fehlauer from comment #3) > Marcel: It would be great if you could add the version of Poppler in use. > You can check with "rpm -qi libpoppler-qt5-1". The Poppler version is attached below: Name : libpoppler-qt5-1 Version : 0.62.0 Release : 2.1 Architecture: x86_64 Install Date: Mon 22 Jan 2018 10:46:37 PM GMT Group : System/Libraries Size : 534592 License : GPL-2.0 or GPL-3.0 Signature : RSA/SHA256, Sat 20 Jan 2018 01:58:19 PM GMT, Key ID b88b2fd43dbdc284 Source RPM : poppler-qt5-0.62.0-2.1.src.rpm Build Date : Sat 16 Dec 2017 12:00:00 PM GMT Build Host : build74 Relocations : (not relocatable) Packager : https://bugs.opensuse.org Vendor : openSUSE URL : https://poppler.freedesktop.org/ Summary : Qt5 wrapper for the Poppler PDF rendering library Description : Poppler is a PDF rendering library, forked from the xpdf PDF viewer developed by Derek Noonburg of Glyph and Cog, LLC. Distribution: openSUSE Tumbleweed
Thanks. I tried those exact versions, nothing too unsual so far (Poppler is not the fastest for image-heavy pages – the blurriness you see might just be an upscaled pixmap shown from the render cache while rendering the actual page). Nevertheless, this might be a regression either in Poppler (general regression) or in Okular (HiDPI regression, or by using some of the new features enabled by a newer Poppler). Here is what you could try next: 0. Specify a page, zoom level and what you were doing exactly, so we are talking about the same thing. 1. Figure out what versions of Okular and Poppler were working "extremely fast" before you upgraded. 2. Test in non-HiDPI mode: In "kcmshell5 kcm_kscreen", set scaling to 1.0 and relogin. 3. Open https://phabricator.kde.org/D8379#164630, grep for "QT_SCALE_FACTOR", watch the accompanying video and let us know if you are experiencing a similar issue (rerendering instead of using the tile cache for HiDPI).
Marcel, does comment #5 help to resolve the issue?
(In reply to Christoph Feck from comment #6) > Marcel, does comment #5 help to resolve the issue? Sorry, I haven't do the test. But I think it might actually because the figures in those PDFs contain too many data points. So it takes time to render them as mentioned in the comments.
Closing as WORKSFORME, because it's not reproducible and we cannot determine whether the version upgrade and/or switch to HiDPI is the problem, or it is just slow in general. We can reopen if you have more information.